The most abundant substance in the urinary free steroid fraction of patients with primary aldosteronism has been identified as 18-hydroxycortisol. 18-hydroxycortisol is very likely an adrenocortical secretory product rather than a peripheral metabolite, since it is abundantly synthesized by aldosteronoma tissue slices. The biogenesis of 18-hydroxycortisol takes place from cortisol rather than from 18-hydroxycorticosterone; that is, 17 alpha-precedes 18-hydroxylation. Cortisol 18-hydroxylation appears to be unrelated to the two other types of adrenocortical hydroxylation at this position. The pathway is present to a small extent in the normal human adrenal cortex and is only moderately stimulated by ACTH. Cortisol 18-hydroxylation is markedly accentuated in two circumstances: in the aldosteronoma cell where its presence may serve to distinguish tumor from bilateral hyperplasia and in ACTH-stimulatable hyperaldosteronism where it represents the first qualitative steroid biochemical abnormality to be demonstrated and as such may be useful in diagnosis and genetic studies. The possible contribution of 18-hydroxycortisol to the severity of the clinical manifestations of mineralocorticoid excess in these two types of aldosteronism remains to be explored.

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1945benefit from both beta-blockade and ACE inhibition. However, his blood pressure was typically only 110/70 mm Hg, so only one agent could be administered, and given the frequent ventricular ectopy, his doctors elected to treat with a low dose of metoprolol succinate. Dudzinski and Schrager ask readers to keep in mind the varied presentations of polyarteritis nodosa. A more exhaustive differential diagnosis for this patient would include polyarteritis nodosa, since it can result in both renal and myocardial infarction. However, this patient had no cutaneous lesions or neuropathy, 3 had sinus bradycardia rather than tachycardia, and was found on angiography to have only "a subtle irregularity" of the midportion of the left anterior descending coronary artery; there was no evidence of aneurysms, obstruction, nodularity, dissection, or thrombosis, which would suggest polyarteritis nodosa. Moreover, since the left ventricular apical aneurysm did not appear to be consistent with a myocardial infarction, it seemed unlikely that the aneurysm was the result of vasculitis or other pathology of the coronary artery. Therefore, although the diagnosis of polyarteritis nodosa could not be formally excluded, it seemed insufficiently likely to warrant discussion, particularly in view of the limited space available in the article.

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Remediation of hazardous waste sites requires efficient and cost-effective methods to assess the extent of contamination by toxic substances including dioxin-like chemicals. Traditionally, dioxin-like contamination has been assessed by gas chromatography/high-resolution mass spectrometry (GC/MS) analysis for specific polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyl congeners. Toxic equivalency factors for these congeners are then used to estimate the overall dioxin toxic equivalency (TEQ) of complex mixtures found in samples. The XDS-CALUX bioassay estimates contamination by dioxin-like chemicals in a sample extract by measuring expression of a sensitive reporter gene in genetically engineered cells. The output of the XDS-CALUX assay is a CALUX-TEQ value, calibrated based on TCDD standards. Soil samples taken from a variety of hazardous waste sites were measured using the XDS-CALUX bioassay and GC/MS. TEQ and CALUX-TEQ from these methods were compared, and a mathematical model was developed describing the relationship between these two data sets: log(TEQ) = 0.654 x log(CALUX-TEQ) + 0.058-(log(CALUX-TEQ))2. Applying this equation to these samples showed that predicted and GC/MS measured TEQ values strongly correlate (R2 = 0.876) and that TEQ values predicted from CALUX-TEQ were on average nearly identical to the GC/MS-TEQ. The ability of XDS-CALUX bioassay data to predict GC/MS-derived TEQ data should make this procedure useful in risk assessment and management decisions.